The present invention is directed generally to circuit condition monitoring systems for power distribution systems, and more particularly to a connector component for such systems having an integral test point socket for receiving a circuit condition test module.
In the operation of electrical power distribution systems it is frequently necessary to monitor circuit parameters such as current and voltage at a particular location to detect the occurrence of a fault current or loss of voltage at the location. To this end, distribution systems have been provided with test points at various locations by means of which monitoring devices such as fault indicators are capacitively coupled to conductors of the systems. Typically, such test points are in the form of exposed metallic contacts imbedded in the housing of a system connector component, such as elbow-type connectors illustrated, for example, in U.S. Pat. Nos. 4,263,550 and 4,375,617 of the present inventor, and available commercially, for example, as the Elastimold type 376LR connector, or similar connector manufactured by RTE Corporation. Such elbow connectors are typically used for connecting a system cable to the terminal of a system component, such as a transformer or relay.
Various types of circuit condition indicating modules have been installed on such test points, including, for example, fault indicators as described in U.S. Pat. Nos. 4,234,847, 4,438,403, 4,424,512 and 4,458,198 of the present inventor, and voltage indicators as described in U.S. Pat. Nos. 4,152,643, 4,251,770, 4,550,288 and 4,641,220 of the present inventor.
One drawback of prior test point constructions is the use of the metallic contact on the surface of the connector. This not only increases the cost of manufacture of the test point, but also creates a need to cap the contact when the test point was not in use to avoid the perception of a shock hazard. The present invention provides a system for monitoring voltage and/or current on a system conductor which by providing a test point socket of novel construction avoids the need for an exposed metallic contact and the attendant complexity of construction. The system further provides a circuit condition monitoring module which can be installed on prior metallic contact-type test points as well as on test point sockets constructed in accordance with the invention, and which in at least one embodiment completely avoids the need for exposed contacts on the module housing thereof.